Do you know the old wheelbarrow joke? It's truly funny only to grandpas and the grandkids they tell it to, so I won't bother with the elaborate setup. For years a factory worker pushes a wheelbarrow full of straw past a security guard on his way out. Suspicious that the guy is stealing something, the guard looks in the straw but can't find anything. Finally, when the worker is retiring, the guard asks, "I know you've been stealing something -- can you tell me what it is?

The guy smiles and says, "Wheelbarrows."

That joke keeps popping into my head whenever I hear Hillary Clinton's defenders say there's no evidence of a quid pro quo in the fresh batch of emails released this week. According to many Republican critics, the trove provides fresh evidence that the Clinton Foundation was, in Donald Trump's words, a "pay-to-play" scheme, selling access to and favors from the secretary of state.

The Clinton team says there's no proof of that. Both Clinton and many of her critics can get ahead of the facts, though in opposite directions. But one thing is clear: Clinton lied. That's not shocking; she's famous for doing that.

Just last month, Clinton said, "There is absolutely no connection between anything that I did as secretary of state and the Clinton Foundation." During her confirmation hearings, members of the Obama administration and Congress extracted assurances from Clinton that there would be a high wall between her State Department and her family's foundation. It turned out it was more like a turnstile.

Former Clinton Foundation official Doug Band would contact Huma Abedin, Hillary's closest aide, when he needed a "favor" for a "friend" (his words) -- and the friend would in many cases be a major donor to the Clinton Foundation. Radio host Hugh Hewitt tartly describes the Clinton Foundation as providing "concierge service" to the State Department.

While everyone but ardent Clinton surrogates can agree that the whole thing looks bad, there's ample disagreement about whether there's any fire under all the smoke. The Clinton campaign insists that there's no evidence of a quid pro quo in any of the newly released emails. In other words, there isn't an email saying something like, "If you donate $10 million to the Clinton Foundation, you can be ambassador to Kenya. For $20 million, we'll exempt you from the ban on importing baby elephant ivory."

To which the obvious response is, "Duh." Some things just aren't put in writing.

She may or may not be guilty of selling favors. But if she is, I very much doubt we'll find evidence of it in an email.

This whole argument misses the point. What we know from these emails, particularly thanks to an analysis by the Associated Press, is that Clinton or other State Department officials agreed to meet or talk on the phone with a large number of Clinton Foundation donors. Some of these meetings probably would have happened if the foundation never existed. But clearly some wouldn't have.

Team Clinton wants to say that even though these meetings and conversations took place, there's no evidence that anyone was granted a special favor.

Fine. Maybe. We'll see. But even if that's true, is there any evidence that the Clinton Foundation wasn't eager to leave the impression that a donation couldn't hurt your chances with the State Department?

This brings me back to the wheelbarrow joke. The meetings (and phone calls) are the wheelbarrows. It really doesn't matter if there's nothing "inside" the wheelbarrows; the meetings and conversations alone were valuable.

Being able to say to business partners, creditors, local politicians, etc., "When I met with Secretary of State Clinton last week ..." is a gift. In America and even more so abroad, possessing a reputation for having friends in the highest places is a priceless asset.

All campaigns understand this. Donors could always just send the check by mail. But politicians understand that one of the things a donor is "buying" is the ability to strut like an insider and dine out on your political connections.

When Bill Clinton rented out the Lincoln Bedroom in the White House to big donors, the donors didn't get to keep the furniture, but they did get to begin sentences, "The last time I stayed at the White House ..."

The Clinton Foundation may not have sold any policy changes, but it definitely sold the wheelbarrows.